Tape drive leader connection sensing assembly

ABSTRACT

A sensing assembly for use in determining if magnetic tape within a single reel tape cartridge properly disconnects from a takeup reel within a tape drive during unloading of the tape cartridge, so that the tape cartridge can be removed from the tape drive without damaging the tape media and rendering the tape drive inoperable. The sensing assembly may be electrical or electomechanical and comprises at least one sensing apparatus for providing feedback on the position of the takeup leader. The position of the takeup leader is used to determine if the tape cartridge leader disconnects from the takeup leader. The sensing assembly may be utilized within a tape drive or with a test fixture for testing a plurality of disconnect operations.

FIELD OF THE INVENTION

[0001] The invention relates to digital tape drive storage devices, andin particular, to a sensing assembly for determining the connectionstatus between magnetic tape within the tape cartridge and a takeup reelwithin a digital tape drive.

Problem

[0002] Digital data is stored on tape drives utilizing a variety ofdesigns, but in all cases, magnetic tape media is wound between a pairof tape reels as data is transferred to or from the tape media. In theart of data storage, the physical space required to store data is animportant concern. To conserve space, tape drives often use a singlereel tape cartridge design, which utilizes a supply reel located withinthe tape cartridge and a takeup reel located within the tape drive.After the tape cartridge is inserted into the tape drive, the magnetictape must be connected to the takeup reel. Various methods have beenemployed to make this connection. One such method connects the magnetictape to the takeup reel via a buckle between a tape cartridge leader anda takeup leader as described in U.S. Pat. No. 4,572,460.

[0003] The magnetic tape within the tape cartridge is terminated at oneend by the tape cartridge leader, which is a strong flexible plasticstrip containing an ovular aperture on its distal end. The takeup leaderis a similar strong flexible plastic strip attached at one end to thetakeup reel. The other end has a stem and tab designed to buckle withthe ovular aperture on the tape cartridge leader. When the tapecartridge is inserted into the tape drive, the takeup leader and tapecartridge leader are positioned to buckle together. This system improvedon prior art systems employing a combination of vacuum and air pressureto guide the tape through a path, but still results in connectionfailures due to wear, misalignment or other causes.

[0004] When the tape cartridge is ejected, first the two leaders shouldbecome separated or disconnected to allow the tape cartridge to beremoved from the tape drive. When the tape cartridge is ejected whilethe two leaders are still connected, damage can occur to both leaders,rendering the tape drive inoperable and the tape cartridge damaged. Inthe prior art, disconnect failures were not always detected by the tapedrive. Due to the nature of the tape media, once the tape media withinthe tape drive is damaged, the data previously recorded on the tapemedia is not recoverable. In addition, because the disconnectionmechanism wears out over time, the problem of disconnection failures ismost common in high duty cycle applications, where it causes the mostdamage. For example, in applications such as library tape drive systems,a broken tape results in an eject failure. The library is theninoperable since one of the tape cartridge leaders failed to disconnectfrom the takeup leader.

[0005] A sensing assembly for use in determining if magnetic tape withinthe single reel tape cartridge properly connects to the take up reelwithin the tape drive during loading of the tape cartridge is disclosedby Zweighaft (U.S. Pat. No. 6,186,430). The sensing apparatus disclosedin '430, in conjunction with a processor detects various movements inthe tape drive consistent with specific connection statuses, namely,proper connection and connection failure. Detecting movement first ofthe freely rotating supply reel and then the takeup reel as the supplyreel is slightly energizes provides confirmation that the connectionexists.

[0006] While the apparatus in '430 detects connection status when thetape cartridge is inserted into the tape drive, the apparatus does notdetect a failure during disconnection of the takeup leader from the tapecartridge leader when a tape cartridge is ejected from the tape drive.Failure of the takeup leader and the tape cartridge leader to disconnectwhen the tape cartridge is ejected from the tape drive results in damageto the takeup leader and the tape media within the tape cartridge. Oncethe tape media within the tape cartridge is damaged, the data previouslystored on the tape media can not be recovered.

[0007] For these reasons, it is desirable to have a sensing mechanismthat detects a failure of the takeup leader to disconnect from a tapecartridge leader and alerts an operator of the disconnection failure.

Solution

[0008] The present tape drive sensing assembly overcomes the problemsoutlined above and advances the art by providing an apparatus and methodfor testing the disconnection status of the tape cartridge leader fromthe takeup leader prior to removal of the tape cartridge from the tapedrive. A sensing assembly provides a means for notifying an operatorwhen the takeup leader and tape cartridge leader fail to properlydisconnect.

[0009] The sensing assembly detects the position of the takeup leaderfollowing a disconnection operation to determine the successfulness ofthe unbuckle operation. If the disconnection operation fails todisconnect the tape cartridge leader from the takeup leader, the sensingassembly generates a signal that can be used to inform the operator ofthe disconnection failure.

[0010] In an alternate embodiment the present tape drive sensingassembly provides an apparatus and method for testing repeateddisconnection operations in a laboratory environment. The presentsensing assembly can be used to test a tape drive of a variety that doesnot include a sensing mechanism built into the tape drive. It may beused as part of a test apparatus to sense when a disconnect failureoccurs in the course of continual insertion/ejection cycling forimproving the reliability of the tape drive. Testing the single reeltape drive utilizing the sensing assembly may be used to reduce thenumber of disconnection failures in the tape drives in the field.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1, illustrates a tape drive embodying the sensing assembly ofthe present tape drive leader connection sensing assembly;

[0012]FIG. 2, illustrates a close up view of the connection between thetape cartridge leader and the takeup leader;

[0013]FIG. 3 is a close up perspective view of the takeup leader in adisconnected position;

[0014]FIG. 4 is a close up perspective view illustrating failure of thetape cartridge leader and the takeup leader to disconnect;

[0015]FIG. 5 is another close up perspective view illustrating failureof the tape cartridge leader and the takeup leader to disconnect;

[0016]FIG. 6 is a close up perspective view of an embodiment of thepresent tape drive leader connection sensing assembly;

[0017]FIG. 7 is a close up perspective top view of a portion of anotherembodiment utilizing the present tape drive leader connection sensingassembly in position for testing a disconnection;

[0018]FIG. 8 is a close up perspective top view of a portion of theembodiment of FIG. 7 sensing assembly testing a proper disconnection;

[0019]FIG. 9 is a close up perspective side view of a portion of thealternative embodiment of FIG. 7 testing a failed disconnection;

[0020]FIG. 10 is a top view of tape drive wherein the takeup leaderfailed to disconnect from the tape cartridge leader; and

[0021]FIG. 11 is a flow diagram of the operating steps in thealternative embodiment of FIG. 7.

DETAILED DESCRIPTION

[0022] The misbuckle detector summarized above and defined by theenumerated claims may be better understood by referring to the followingdetailed description, which should be read in conjunction with theaccompanying drawings. This detailed description of the preferredembodiment is not intended to limit the enumerated claims, but to serveas a particular example thereof. In addition, the phraseology andterminology employed herein is for the purpose of description, and notof limitation.

[0023]FIG. 1 illustrates tape drive 100 embodying the sensing assemblyof the present invention. By way of background, the tape loadingoperation begins when tape cartridge 102 is inserted into tape drive100. Tape cartridge 102 houses a length of magnetic tape 142 woundaround supply reel 114. Magnetic tape 142 includes a tape cartridgeleader 104 connected to its free end. Takeup reel 112 includes a similartakeup leader 106. Takeup leader 106 connects to the takeup reel 112 andwinds around guide rollers 144, 148, 140, and 138 where it hooks oncatch 118.

[0024] When tape cartridge 102 is fully inserted into tape drive 100,tape cartridge leader 104 is positioned to connect with takeup leader106. Positioning lever 110 positions tape cartridge leader 104 andtakeup leader 106 for connection and disconnection. The loading of tapecartridge 102 engages cartridge present switch 126. Microprocessor 122in response to a signal from cartridge present switch 126 initiates theconnection of takeup leader 106 and tape cartridge leader 104. Theconnection between takeup leader 106 and tape cartridge leader 104 is inthe form of a buckle.

[0025]FIG. 2 illustrates a close up view of the buckle between tapecartridge leader 104 and takeup leader 106. Tape cartridge leader 104comprises a first elongated flexible plastic strip 202 containing anovular aperture 204 defined therein. Takeup leader 106 comprises asimilar second elongated flexible plastic strip 206, which contains anintegrally formed stem 212 and tab 210 that are proportioned to bucklewith ovular aperture 204 as illustrated by FIG. 2. Takeup leader 106also includes an elongated rectangular slot 208 that is proportioned tohook onto catch 118 of FIG. 1.

[0026] Referring back to FIG. 1, in the buckled position, the takeupleader and connected tape cartridge leader are within the tape pathaligned with catch 118 and the positioning lever 110. Microprocessor 122responsive to a signal to eject the tape cartridge rotates catch 118from loaded position clockwise to the unloaded position thereby catchingtakeup leader 106 while positioning lever 110 holds takeup leader 106 sothat stem 212 is extracted through aperture 204. The leaders are nowpositioned such that the tape cartridge 102 may be pulled straight outof the tape drive. The tape drive has an eject mechanism that pushes thetape cartridge partially out of the tape drive. This completes thedisconnection between the tape cartridge leader 104 and takeup leader106. If tape cartridge leader 104 and takeup leader 106 do not unbuckleproperly due to wear, misalignment or other causes, takeup leader 106may be pulled past catch 118 and eventually stretch the tape media asthe tape cartridge is removed from the tape drive, thereby damaging thetape media. Tape path 136 comprises the path of magnetic tape 142 fromits origination on supply reel 114 to its destination on takeup reel112, including supply motor 116, takeup motor 108, and load motor 128.Tape path 136 also includes positioning lever 110, catch 118, aplurality of guide rollers e.g. 148, 138, 140, and 144, and takeup reel112.

[0027] In the event that a bad disconnection causes the tape cartridgeleader to pull the takeup leader 106 as the tape cartridge is removedfrom the tape drive, the tape media within the tape cartridge may bedamaged. The length of tape media within the tape cartridge is drawntaunt as the tape cartridge is moved further from the takeup reel,stretching the tape media and rendering the tape drive and the tapecartridge inoperable. To operate again, the tape drive 100 must bedisassembled so that the takeup leader and the tape cartridge leader maybe disconnected and the takeup leader 106 can be reconnected to catch118. The section of the length of tape media within the tape cartridgeis damaged and the data recorded thereon may be permanently destroyed.

[0028] Leader Connection Status:

[0029] Under normal operating conditions, when the takeup leader isdisconnected from the tape cartridge leader, catch 118 is hooked throughslot 208 and tab 210 of the takeup leader rests against positioninglever 110 as illustrated in the close up perspective view of FIG. 3.Microprocessor 122 in response to a signal to eject the tape cartridge102 initiates the disconnection operation to disconnect the takeupleader 106 from the tape cartridge leader 104. When the disconnectionfails as illustrated in FIG. 4, the takeup leader 106 remains connectedto the tape cartridge leader 104 as the tape cartridge is ejected fromthe tape drive. The takeup leader may remain hooked to catch 118 asillustrated in FIG. 4 or may be unhooked as illustrated in FIG. 5. Inboth failed configurations, the takeup leader fails to return to itsdisconnected position in contact with positioning lever 110.

[0030] Therefore, determining the position of the takeup leaderfollowing a disconnection operation is indicative of the disconnectionstatus. Once a disconnection fails, the tape cartridge should not beremoved from the tape drive. Removal of the tape cartridge from the tapedrive will damage the tape media within the tape cartridge destroyingthe data previously stored on the tape media. Failure of the tape driveto notify the operator of the failed disconnection results in theoperator removing the tape cartridge from the tape drive and therebydamaging the tape media. The sensing assembly may be electrical orelectromechanical. In an embodiment the sensing assembly comprises asensing device located near the tape path for monitoring the position ofthe takeup leader. When the takeup leader is connected to the tapecartridge leader, the takeup leader is positioned within the tape path.As previously discussed, when the takeup leader and the tape cartridgeleader are disconnected, the takeup leader is in contact with or inclose proximity to the positioning lever. Thus, a sensing device locatedon the positioning lever may be used to sense the position of the lever.

[0031] For example, the sensing device in FIG. 6 is a positioning sensor120 connected within an area on the positioning lever 110 near where thetakeup leader 106 contacts the positioning lever 110 when disconnected.The sensing device may be a light emitting or light detecting devicehaving a corresponding light detecting or light emitting sourcepositioned to complete or break a light path when the takeup leader isdisconnected. Following an unbuckle operation, the sensing devicedetects the position of the takeup leader and provides feedback to amicroprocessor in response to the position of the takeup leader withinthe tape drive. The sensing device may be an alternative sensing devicesuch as a pressure sensitive device for sensing the contact between thetakeup leader 106 and the positioning lever 110.

[0032] Microprocessor 122 provides the signaling required forcontrolling the operation of tape drive 100. Position sensor 120 may beconnected to any location where the position of the takeup leader 106can be sensed. Microprocessor 122 and signal processing circuit 124 area conventional circuit and processor configured with software to operatein accord with the various embodiments of the sensing assembly.

[0033] Following a proper disconnection, the takeup leader is at restand in close proximity to the positioning lever 110, as illustrated inFIG. 3, partially blocking the position sensor 120. The signal sent bythe position sensor 120 to the microprocessor 122 via signal processingcircuit 124 indicates at least a partial blockage of the position sensor120. In response to the passing status of the disconnection, themicroprocessor may indicate via a control panel (not illustrated) on thetape drive that the tape cartridge is ready for removal. Failure of thetakeup leader and the tape cartridge leader to disconnect results in thetakeup leader retaining connection to the tape cartridge leader andtherefore located a distance from the position sensor 120 as illustratedin FIGS. 4 and 5. The microprocessor checks the signals received fromposition sensor 120 following the disconnection to determine theposition of the takeup leader. If the signal received by themicroprocessor indicated that the disconnect failed, microprocessor 122may be programmed to alert operators by providing a visual and/or audiomessage. Microprocessor 122 may also be programmed for various otherresponses, including but not limited to performing a pre-programmednumber of disconnection attempts before alerting the operator of thedisconnection failure.

[0034] Alternatively, the sensing assembly may be an electromechanicalapparatus for detecting the position of the takeup leader following adisconnection operation. In this alternative embodiment, theelectromechanical apparatus may be used to detect the position of thetakeup leader following an unbuckle operation. Referring to theelectromechanical apparatus of FIG. 7, the primary components are arotatable barrel 310 and an elongated member 318 extending through thebarrel 310 and protruding downwardly behind the tape path and betweenthe catch 118 and the positioning lever 110 and extending upwardly inthe path of a sensing mechanism. The sensing mechanism provides a methodfor detecting a rotational movement of the barrel 310 and coupledelongated member 318. The sensing mechanism 322 detects a change in therotational position of the elongated rod member 318 and providesfeedback to the microprocessor in response to the rotation wherein therotation reflects the position of the takeup leader within the tapepath. Thus, the rotational movement is used to determine the position ofthe takeup leader and therefore if the buckle is disconnected. For thepurpose of illustration, the sensing mechanism 322 is describedutilizing a light emitting source 314 and a corresponding lightdetecting device 316 although other sensing mechanisms may besubstituted. Those skilled in the art will appreciate numerousvariations in the sensing configuration and operation that are withinthe scope of the present sensing assembly. Those skilled in the art willalso appreciate how the principles illustrated in the two embodimentsdescribed below can be used in other embodiments of the sensing assemblyas well as in other tape drive models that employ various leaderdisconnection methods and apparatus.

[0035] Still referring to FIG. 7, U-shaped member 322 attaches to aretractable arm (not shown) and partially surrounds the upwardlyextending portion of the elongated rod 318 and houses light emittingsource 314 and light detector 316 on opposing sides of U-shaped member322. The light emitting source 314 and light detector 316 are positionedsuch that when the elongated rod 318 is stationary, the elongated rod318 blocks the light emitted by light emitting source 314. The initialposition of the elongated rod 318 is in an area 150 between catch 118and positioning lever 110, away from the tape path. The retractable armmoves the barrel 310 from the initial position toward the tape pathtraveling out of area 150.

[0036] As previously discussed, when the buckle between takeup leader106 and the tape cartridge leader 104 disconnects, takeup leader 116returns to a disconnected position in contact with positioning lever110, thus enclosing the area 150 between catch 118 and positioning lever110 as illustrated in FIG. 3. Referring back to FIGS. 4 and 5, when thedisconnection fails, takeup leader 106 remains buckled to tape cartridgeleader 104, drawing takeup leader 106 away from the positioning lever110 as the tape cartridge 102 is ejected from the tape drive 100. Thus,determining the position of takeup leader 106 following a disconnectionoperation provides a method for determining the connection statusbetween takeup leader 106 and tape cartridge leader 104.

[0037] The retractable arm moves the barrel 310 towards the leader tip210 following an unbuckle operation. If the takeup leader and the tapecartridge leader properly disconnect, the takeup leader moves from area150 to the disconnected position in contact with positioning lever 110as illustrated in FIG. 8. In the case of a successful disconnect, FIGS.7 and 8, as the elongated rod 318 pulls against takeup leader 206,barrel 310 is free to pivot. Rotation of the barrel 310 rotateselongated rod 318 out of the path between the light emitting source 314and the light detector 316. In response to the rotation of the elongatedrod 318, the light detector 316 provides feedback to the microprocessor.Detection of light by the light detector 316 indicates that the takeupleader and the tape cartridge leader properly disconnected.

[0038] Referring to the failed disconnection condition of FIG. 9, whenthe retractable arm moves barrel 310 forward towards takeup leader 206following a failed disconnection, the barrel 310 does not rotate.Referring to FIG. 10, when the takeup leader 106 and the tape cartridgeleader 104 fail to disconnect, the takeup leader remains in the tapepath. When the retractable arm moved the elongated rod 318 in thedirection of the tape path, the elongated rod 318 does not encounter thetakeup leader 106 and therefore travels outside of area 150 that isenclosed when the takeup leader is in its disconnected position. Barrel310 and elongated rod 318 do not rotate when the elongated rod 318 isfree to travel out of area 150 and toward the tape path.

[0039] Thus, the present tape drive leader connection sensing assemblyprovides a method for determining the position of the takeup leader andnotifying the operator of the failed disconnection such as providing anaudible sound or visual display to alert the operator of the faileddisconnection and thereby prevent the operator from pulling the tapecartridge out of the tape drive and damaging the tape media therein. Useof the present tape drive connection sensing assembly for a tape driveinstalled in a tape cartridge library, or autoloader, apparatus providesa method for notifying the tape cartridge system and the operator thatthe takeup leader has failed to disconnect from the tape cartridgeleader.

[0040] Tape Drive Leader Connection Test Apparatus:

[0041] The present tape drive connection sensing assembly also providesa method for testing the disconnection operation of the tape drive in alaboratory environment. The sensing assembly may be connected to a testfixture and positioned above a tape drive for testing repeated unbuckleoperations. In the testing configuration, a controller circuit mayinitiate an unbuckle operation of the tape drive. Following the unbuckleoperation, the position of the takeup leader is detected by the testfixture sensing assembly. In response to the position of the takeupleader, the sensing device may provide feedback to the controllerindicating the position of the takeup leader. Recording the number ofunbuckle operation attempts and the number of attempts that successfullydisconnect the takeup leader from the tape cartridge leader provides amethod for collecting reliability data.

[0042] Testing repeated tape drive unbuckle operations provides datathat may be used to improve the operational characteristics of the tapedrive, the takeup leader and the tape cartridge unbuckling operation.Improved performance of the tape drive unbuckle operation reduces thepossibility of an operator damaging the tape media within the tapecartridge. Providing an alert for the operation when a failed unbuckleoperation is detected allows the operator to discontinue use of the tapedrive prior to damaging the tape media rendering the previously recordeddata unrecoverable.

[0043] Electromechanical Sensing Assembly Operation:

[0044] The control circuit (not shown) extends/retracts a retractablearm to initially position elongated rod 318 in area 150 between catch118 and positioning lever 110 and behind tape path as previouslydescribed. FIGS. 7, 8 and 9 illustrate close up top views of a sectionof the electromechanical sensing assembly and tape drive 100. To providea view of the elongated rod 318 extending into area 150 between the tapedrive catch 118 and the positioning lever 110, housing 320 andretractable arm 330 are not shown.

[0045] Referring to the operational flow diagram of FIG. 11 inconjunction with the perspective view of FIG. 7, following an unbuckleoperation by the tape drive in step 400 the takeup leader and tapecartridge leader may properly disconnect in step 402. The connectionstatus of the takeup leader and tape cartridge leader is determined bythe position of the takeup leader. To test the connection status, thetest fixture extends retractable arm 330 in step 404 moving elongatedrod 318 in front of positioning lever 110 in the direction of the tapecartridge. If elongated rod 318 encounters takeup leader 106 resting inclose proximity to positioning lever 110 in step 406, retention ofelongated rod 318 in enclosed area 150 causes drum 310 and coupledelongated rod 318 to rotate in step 408. Rotational movement ofelongated rod 318 in step 408 opens the light path between lightemitting source 314 and light detector 316 in step 410. In response todetecting light, the light detector 116 send a signal to themicroprocessor in step 412 indicating that the takeup leader 106 and thetape cartridge leader 104 properly disconnected in step 402.

[0046] If elongated rod 318 does not encounter takeup leader 106 in step406 elongated rod 318 moves out of area 150 in step 420. The light pathbetween light emitting source 114 and light detector 116 is not broken.Absence of a signal from the light detector 116 following the disconnecttest, indicates that the takeup leader 106 and the tape cartridge leader104 disconnection failed in step 402. In response to the faileddisconnect, the microprocessor may provide an audible or visual signalto the operator in step 424 to alert the operator that the disconnectionfailed and that the tape cartridge should not be removed from the tapedrive.

[0047] A preferred feature of both embodiments is to provide timelyfeedback on the disconnection status. As to alternative embodiments,those skilled in the art will appreciate that the present sensingassembly may be utilized to detect numerous variables within tape drivethat indicate disconnection status. In addition, the present sensingassembly may be located on either side of the tape path and may be usedto detect variables internally or externally to tape path that indicateconnection status.

[0048] It is apparent that there has been described, a sensing assemblyfor determining if magnetic tape in a tape cartridge is properlyconnected to a tape drive, that fully satisfies the objects, aims, andadvantages set forth above. While the sensing assembly has beendescribed in conjunction with specific embodiments thereof, it isevident that many alternatives, modifications, and/or variations can bedevised by those skilled in the art in light of the foregoingdescription. Accordingly, this description is intended to embrace allsuch alternatives, modifications and variations as fall within thespirit and scope of the appended claims.

What is claimed is:
 1. A sensing assembly for use with a tape driveemploying a single reel equipped with a takeup leader forinterconnecting with a tape cartridge leader connected to a length oftape media located within a tape cartridge, to determine if said tapecartridge leader disconnects from said takeup leader during unloading ofsaid tape cartridge, so that said tape cartridge can be removed fromsaid tape drive without damaging said length of tape media, comprising:means for disconnecting said takeup leader from said tape cartridgeleader prior to removing said tape cartridge from said tape drive; andat least one leader position detecting means to detect a position of atleast one of said tape cartridge leader and said takeup leader followingsaid disconnect, said position being used to determine if said tapecartridge leader disconnects from said takeup leader.
 2. The sensingassembly of claim 1 further comprising: a processing means, responsiveto said detected position of said at least one of said takeup leader andsaid tape cartridge leader, for determining if said tape cartridgeleader disconnects from said takeup leader.
 3. The sensing assembly ofclaim 1, wherein said at least one leader position detecting meanscomprises: a means for sensing movably located a distance from a tapepath; a means for moving said movable sensing means from an initialposition into said tape path to detect said position of at least one ofsaid takeup leader and said tape cartridge leader.
 4. The sensingassembly of claim 3, wherein said sensing means is rotatable andcomprises: a means for sensing a rotational position of said rotatablesensing means said rotational position for determining if said tapecartridge leader disconnects from said takeup leader.
 5. A test fixturefor use testing a tape drive employing a single reel equipped with atakeup leader for interconnecting with a tape cartridge leader connectedto a length of tape media located within a tape cartridge, to determineif said tape cartridge leader disconnects from said takeup leader duringunloading of said tape cartridge, comprising: a connecting means forremovably connecting said tape drive to said test fixture; means fordisconnecting said takeup leader from said tape cartridge leader forremoving said tape cartridge from said tape drive; and at least oneleader position detecting means to detect a position of at least one ofsaid tape cartridge leader and said takeup leader following saiddisconnect, said position being used to determine if said tape cartridgeleader disconnects from said takeup leader.
 6. The test fixture of claim5 further comprising: a processing means, responsive to said detectedposition of said at least one of said takeup leader and said tapecartridge leader, for determining if said tape cartridge leaderdisconnects from said takeup leader.
 7. The test fixture of claim 5,wherein said at least one leader position detecting means comprises: amovable means for sensing insertable into said tape drive a distancefrom a tape path with said tape drive; a means for moving said movablesensing means from an initial position into said tape path to detectsaid position of at least one of said takeup leader and said tapecartridge leader for determining if said tape cartridge leaderdisconnects from said takeup leader.
 8. The sensing assembly of claim 7,wherein said sensing means is rotatable and comprises: a means forsensing a rotational position of said rotatable sensing means saidrotational position for determining if said tape cartridge leaderdisconnects from said takeup leader.
 9. The test fixture of claim 7,wherein said movable sensing means comprises: a rotatable memberextending downward into said tape drive said distance from said tapepath; and a means for sensing connected with said rotatable member forsensing a rotational position of said rotatable member.
 10. A sensingassembly for use with a tape drive employing a single reel equipped witha takeup leader for interconnecting with a tape cartridge leaderconnected to a tape media located within a tape cartridge, to determineif said tape cartridge leader disconnects from said takeup leader duringunloading of said tape cartridge from said tape drive, comprising: adisconnection apparatus for disconnecting said tape cartridge leaderfrom said takeup leader prior to removing said tape cartridge from saidtape drive; a sensing device for sensing a position of said takeupleader following said disconnect; and a processor responsive to saidsensed position of said takeup leader for determining if said tapecartridge leader disconnects from said takeup leader.
 11. The sensingassembly of claim 10, wherein said sensing device comprises: a rotatablesensing ably located a distance from a tape path; a means for movingsaid movable sensing means from an initial position into said tape pathto detect said position of said takeup leader; and a means for sensing arotational position of said rotatable sensing means said rotationalposition for determining if said tape cartridge leader disconnects fromsaid takeup leader.
 12. A method for determining if a tape cartridgeleader connected to a length of tape media within a tape cartridgedisconnects from a takeup leader within a tape drive employing a singlereel during unloading of said tape cartridge, comprising the step of:(a) executing a disconnection operation to disconnect said tapecartridge leader from said takeup leader; (b) sensing a position of oneof the said tape cartridge leader and said takeup leader following saiddisconnect operation; and (c) determining a connection status of saidtape cartridge leader from said takeup leader.
 13. The method of claim12, wherein said connection determination step comprises the steps of:determining a change in position of one of said tape cartridge leaderand said takeup leader after said disconnection operation; and comparingsaid position change with a threshold to determine if said tapecartridge leader and said takeup leader are disconnected.
 14. The methodof claim 12, further comprising the step of: alerting an operator of adisconnection failure in response to a determination that thedisconnection failed.
 15. The method of claim 12, wherein the positionsensing step further comprises the steps of: positioning a movablesensing assembly a distance from a tape path; moving said movablesensing assembly into said tape path; and sensing a position of saidmovable sensing assembly to determine if said tape cartridge leadersuccessfully disconnected from said takeup leader.